River Systems: Tributaries, Confluence, and Distributaries

Rivers

• A tributary is a stream or river that flows into a larger stream, main stream, or lake, and does not flow directly into a sea or ocean.
• A confluence is the point where two or more bodies of water meet together.
• A distributary is a river or stream that branches off the main stream and flows away, often found in river deltas, resulting from sediment buildup along the main channel.

Map Study

• Maps are important tools in today's practical world, serving as storehouses of information.
• Colors are used to represent different features on topographical maps, such as:
  • Yellow: cultivable land, plateaus, deserts, and plains
  • Green: forest areas or lowland areas
  • White: rocky areas or badland, hence uncultivable land
  • Blue: perennial lined wells, perennial streams, lakes, and ponds, water bodies in general
  • Brown: contour lines, heights, and relief features like mountains
  • Black: dry streams and surveyed trees
  • Red: permanent huts, settlements, cities
• Symbols are used to represent features on maps, such as rivers, ponds, settlements, roads, and trees.

Types of Maps

• Plan: A sketch of a building, school, church, or house, drawn to scale, giving an idea of a small area on a large scale with all necessary details.
• Map: A representation of the Earth or a portion of the Earth drawn to scale on a flat surface, giving a good amount of information at a glance.
• Types of Maps:
  • Large Scale Maps: Show a small area in great detail, e.g., topographical maps and city plans
  • Small Scale Maps: Show a larger area, often used for display purposes, e.g., wall maps and atlas maps

Compass Directions

• The sun rises in the east and sets in the west.
• If facing the sun in the morning, you are facing east; west is behind you, and your left hand points north, while your right hand points south.
• The Pole Star always points north and is visible in the sky, used to find direction.

Scales

• A scale is a measuring line that shows the relationship between the distance between two places on a map and their actual distance on land.
• Types of Scales:
  • Verbal or Statement Scale: Expressed in words, e.g., 1cm on the map represents 50km on the ground.
  • Numerical Fraction or Representative Fraction or R.F.: Expressed as a ratio, e.g., 1:50,000.
  • Graphic or Linear Scale: A line divided into equal parts, each part representing a certain distance on the ground.

Globe

• A globe is a spherical model of the Earth, showing the relative shapes and sizes of continents, countries, and oceans.
• The globe is the only accurate way of showing the three-dimensional model of the Earth.

History of Maps

• The first attempts at collecting maps into a book were made by Gerardus Mercator and Jodocus Hondius in 1636.
• The book featured a picture of Atlas, the Greek mythological giant, holding the Earth on its cover, leading to the naming of the book as an atlas.

Features Formed in Different Stages of a River

• Upper Course: Fast-flowing, eroding the land, creating V-shaped valleys and waterfalls.
• Middle Course: Slowing down, depositing sediment, creating meanders, oxbow lakes, and floodplains.
• Lower Course: Slowing down even further, depositing a large amount of sediment, creating a delta.

Importance of Maps

• Maps are essential for learning and an important tool of a geographer.
• They are used by explorers, reference personnel, city architects, planners, weather-forecasters, motorists, traders, tourists, scouts, and guides.
• Maps are also useful for students to gain knowledge of the world.

Disadvantages of Maps

• Maps, though drawn to scale, become narrow near the Poles due to projections, showing a distorted picture of continents and countries sometimes.
• Maps are a two-dimensional representation of the Earth's surface, showing only a part of the globe on a flat surface.

Directions

• Cardinal Points: North, South, East, and West
• Intermediate Directions: North West (NW), North East (NE), South West (SW), and South East (SE)
• Directions help us study the phenomena of celestial bodies and find our location on a map or globe.